Curbing Interstate Air Pollution: The Clean Air Act Should Be Amended to More Effectively Address Regional Air Pollution Problems

Article excerpt

The national lawmakers and citizens who secured adoption of the Clean Air Act more than 30 years ago were visionaries. They erected a durable statute that is responsible for healthier air for millions of Americans. It is with an abiding sense of regard for this national legacy that carefully tailored statutory improvements could be made to more effectively and efficiently address remaining air pollution problems.

Early Success

The national ambient air quality standards, one of the seminal changes adopted in the 1970 statute, have proven to be the linchpin of air quality progress. These federally established standards are based on a comprehensive assessment of scientific research on the health effects of air pollution. These standards have several important functions. They provide the touchstone for determining healthy and unhealthy air for communities across the country. They also provide the framework for concerted federal and state measures to lower air pollution concentrations in those communities having air pollution levels in excess of the standards, and for strategies to prevent degradation in areas meeting the standards.

One measure of the success of the national ambient air quality standards program is that almost all airborne regulated contaminants have significantly decreased since 1970. Carbon monoxide emissions, for example, were lowered by about 25 percent between 1970 and 2000, and volatile organic compounds were lowered by about 40 percent.

Perhaps the most consequential public health progress under the statute has been the lowering of lead emissions, which is almost solely attributable to phasing out lead in gasoline. The phaseout has lowered emissions by 98 percent since 1970, and the concentration of lead in the atmosphere has dropped by about 94 percent. The lead phaseout, which was critical in reducing the number of U.S. children with elevated blood-lead levels, has been one of the most important environmental health initiatives of the past quarter century. According to the Centers for Disease Control, these levels have declined from 88.2 percent in the late 1970s to 4.4 percent in the early 1990s.

We also have made historic progress in protecting the health of ecosystems. The political logjam in the debate over acid rain was broken by turning to a market-based strategy to curb emissions of sulfur dioxide from power plants. The resulting program has achieved momentous emission reductions at a fraction of the projected costs. While scientists have documented the need for further cuts in both sulfur dioxide and nitrogen oxides to protect ecosystem health, the first round of cuts in sulfur dioxide has proven effective in lowering the high levels of sulfate deposition in our forests, lakes, and streams.

Higher Standards

These programs set the high standard of success we must demand from ongoing efforts under the Clean Air Act to protect public health and the environment. Indeed, a number of serious challenges remain, including lowering carcinogenic diesel particulate emissions from large, diesel-powered, nonroad engines like construction, industrial, and agricultural equipment; curbing the deleterious concentrations of fine particles and ozone smog in communities across the country; continuing efforts to lower toxic emissions from large industrial plants; reducing mercury emissions from power plants; further reducing emissions of both sulfur dioxide and nitrogen oxides to spur recovery of ecosystems threatened by acid rain, and clear the haze in national parks; and tackling the pressing problem of climate change.

Lowering harmful concentrations of fine particles, reducing acid rain, and cutting haze will entail the considerable challenge of abating interstate air pollution. The airborne contaminants that contribute to these problems can travel hundreds of miles from their pollution source. Consequently, effective air pollution management strategies will require lowering pollution levels across broad geographic regions. …